Control system for a vehicle
A control system is disclosed for use in a zero turn vehicle, including an electric controller in communication with a pair of independent drive units. A joystick is pivotable between a plurality of pivot positions, each pivot position corresponding to a particular rotational speed and direction of each driven wheel. A plurality of driving modes stored in the controller each map a different set of speeds and directions for each driven wheel onto the plurality of pivot positions. The joystick may also rotate about a vertical axis to provide zero turn capability. In at least one driving mode, when the rotational speed of one driven wheel is zero, the rotational speed of the other driven wheels is zero, and when the rotational speed of one driven wheel is non-zero, the rotational speed of the other driven wheel is non-zero.
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This application is a continuation of U.S. patent application Ser. No. U.S. 16/213,581, filed on Dec. 7, 2018, which is a continuation of Non-Provisional patent application Ser. No. 15/670,873, filed on Aug. 7, 2017, which is a continuation of U.S. Non-Provisional patent application Ser. No. 14/790,675, filed on Jul. 2, 2015, which claims the benefit of U.S. Provisional Pat. App. No. 62/020,612, filed on Jul. 3, 2014. The contents of these prior applications are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTIONThis disclosure is generally related to drive and directional control devices for vehicles.
This disclosure is generally related to drive and directional control systems for vehicles in general, and more particularly to drive systems and directional control systems for utility vehicles such as, for example, lawn and garden tractors and mowers.
Traditional utility vehicle travel control is accomplished by a combination of driven wheels, steered wheels, a steering control, a transmission control, and a throttle. The operator or user of such a traditional vehicle may first select a forward or reverse gear with the transmission control, then set the throttle to a speed of travel, and then steer the vehicle. This type of vehicle travel control is normally associated with vehicles having a relatively wide turning radius and limited maneuverability in tight quarters.
In an attempt to improve maneuverability, zero turn vehicles, such as zero turn mowers, were introduced. A zero turn style vehicle typically uses independently controlled transaxles or wheel motors to provide steering by selectively speeding up, slowing down, or changing the direction of rotation of the driven wheels on each side of the vehicle. Typically, a user manipulates a pair of levers to control the speed and direction of the output of a transaxle on each side of the vehicle. If the user wishes to move the vehicle forward, he presses both levers forward. If the user wishes to move the vehicle backwards, he pulls the levers back. To steer the vehicle to the left, the right side lever is pushed further than the left, and to execute a very tight turn to the left, the user can pull the left lever back while pressing the right lever forward to execute a zero radius, or near zero radius turn.
The steering wheel method is easy to use but may lack maneuverability and programming flexibility when compared to a joystick control system and the lever activated differential steering systems may simply be more difficult to use for some vehicle operators. This disclosure is directed to addressing the problems and needs of travel control systems in the general area of highly maneuverable utility vehicles.
SUMMARY OF THE INVENTIONThe present invention comprises a control system for a utility vehicle capable of traveling in a variety of different directions and turning in a zero turn manner. The control system incorporates a multi-axis user interface such as a joystick connected to a controller for proportionally controlling the direction and speed of the vehicle, and for providing different manners in which the vehicle may enter zero-turn mode. The joystick may include at least one selector switch, such as a pushbutton, for switching between programmed travel modes or selecting an auxiliary function.
A better understanding of the invention will be obtained from the following detailed descriptions and accompanying drawings, which set forth illustrative embodiments that are indicative of the various ways in which the principals of the invention may be employed.
The description that follows describes, illustrates and exemplifies one or more embodiments of the invention in accordance with its principles. This description is not provided to limit the invention to the embodiments described herein, but rather to explain and teach the principles of the invention in order to enable one of ordinary skill in the art to understand these principles and, with that understanding, be able to apply them to practice not only the embodiments described herein, but also any other embodiment that may come to mind in accordance with these principles. The scope of the invention is intended to cover all such embodiments that may fall within the scope of the appended claims, either literally or under the doctrine of equivalents.
It should be noted that in the description and drawings, like or substantially similar elements may be labeled with the same reference numerals. However, sometimes these elements may be labeled with differing numbers or serial numbers in cases where such labeling facilitates a more clear description. Additionally, the drawings set forth herein are not necessarily drawn to scale, and in some instances proportions may have been exaggerated to more clearly depict certain features. As stated above, this specification is intended to be taken as a whole and interpreted in accordance with the principles of the invention as taught herein and understood by one of ordinary skill in the art.
The electric transaxles 130L and 130R depicted herein may be similar in construction to those depicted in U.S. Pat. No. 8,668,036, the terms of which are incorporated herein by reference. It will be understood that those elements of the vehicle which are important to the ability of the user to turn the vehicle, such as the electric transaxles 130L and 130R, are designated using left and right designations, simply for ease of description. Other elements which may have more than one component such as the alternators 121, but for whom location is not critical, do not use left and right designations.
Additional types of utility vehicles 200, 300, 400, 500 and 600 are depicted in
Controller 332 is depicted as being centrally located under seat 315, but the location of this component and others, such as battery 324, can be modified and are dependent on the vehicle size and other factors. A control panel 350 provides the operator with control of certain vehicle functions and information about the status of vehicle 300. It will be understood that an operator interface, such as control panel 350, may be provided in addition to joystick 140 for any of the vehicles described herein, although this additional operator interface is not shown in order to simplify the other vehicle figures.
Controller 332 receives power from battery 324 and is connected to joystick 140 by conductor 341. Electric displacement actuators 331L, 331R control the output of transaxles 329L, 329R, respectively, based on input from controller 332, and are connected thereto by means of conductors 336. Sensors 333L, 333R also provide controller 332 with information about the position of the swash plates (not shown) inside transaxles 329L, 329R and are connected to controller 332 by means of conductors 338. Speed sensors 335L, 335R are used to indicate the actual speed of rear driven wheels 316L, 316R, and are connected to controller 332 by means of conductors 337. Electric displacement actuators 331L, 331R may be similar to those depicted in U.S. patent application. Ser. No. 14/104,979, now U.S. Pat. No. 9,114,798, the terms of which are incorporated herein by reference. Transaxles 329R and 329L may be Hydro-Gear ZT-2800 integrated zero-turn transaxles, as depicted in U.S. Pat. No 7,134,276, the terms of which are incorporated herein by reference. Electric displacement actuators 331L and 331R are shown as being integral to transaxles 329L, 329R but they could also be separately connected thereto.
It will be understood that the depiction of the batteries 124, 224, 324, 424, 524 and 624 in
The joystick controller assembly disclosed herein could also be used in a vehicle incorporating electric wheel hub motors. For example,
Joystick 140, which is depicted as being the same in each of the vehicle embodiments, is shown in more detail in
Similarly, position 9 in
Position 2 shows both driven wheels moving forward, but with left driven wheel 316L turning faster than right driven wheel 316R, resulting in a relatively gentle turn to the right, as seen in
As joystick 140 is pivoted, or canted, further to the right, it will reach position 4 where right driven wheel 316R is now moving in reverse at a reduced speed (arrow 4b) and left driven wheel 316L is still moving forward at full speed (arrow 4a), resulting in an even more dramatic right hand turn, as shown in
It will be understood that operation in the different quadrants depicted in
Similarly, as the joystick 140 then continues to move in the counter-clockwise direction from position 13 to position 9, the vehicle will leave the left zero turn mode of position 13 and begin backing up, with the rear of the vehicle 300 moving to the right, as shown, e.g., by positions 12, 11 and 10 in
Note also that in
The user could alternate between the programming scheme, or driving modes, of
Each of the plurality of driving modes maps a different set of speeds and directions for each of the driven wheels onto the plurality of pivot positions. A further advantage of the driving mode depicted in
A potential drawback of the driving modes which incorporate stop positions 5 and 13 is that a user driving vehicle 300 in a tight left or right turn, such as one mowing a tight circle around an object, could inadvertently move the joystick to the stopped positions 5 or 13. This may cause aggravation and delay in completing the job. To address this concern,
The “twist” feature of joystick 140 could also be used in different manners, in addition to the twist-to-zero-turn embodiments previously described, and various modifications may be programmed into the controller. For example, the twist capability depicted in
The pushbutton feature of joystick 140 could also be used in different manners. For example, the programming of the controller, such as controller 632 shown in
While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any equivalent thereof.
Claims
1. A control system for use in a vehicle having a pair of drive units, each drive unit independently powering one of a left driven wheel and a right driven wheel of the vehicle, the control system comprising:
- one or more controllers in communication with the pair of drive units; and
- a joystick assembly in communication with the one or more controllers, the joystick assembly comprising a joystick stalk (i) pivotable from a neutral pivot position to a plurality of non-neutral pivot positions about an X-axis and a perpendicular Y-axis meeting at a center point, and (ii) twistable in a first direction and a second direction from a neutral twist position about a stalk axis extending through the center point and the joystick stalk;
- wherein when the joystick stalk is in the neutral pivot position, the stalk axis is perpendicular to both the X-axis and the Y-axis, and when the joystick stalk is in one of the plurality of non-neutral pivot positions the stalk axis is not simultaneously perpendicular to both the X-axis and the Y-axis; and
- wherein the one or more controllers are configured to: determine a current pivot position and a current twist position of the joystick stalk; issue a first set of instructions to the pair of drive units when the joystick stalk is in the neutral twist position and a first non-neutral pivot position; issue a second set of instructions to the pair of drive units when the joystick stalk is in the neutral pivot position and has been twisted from the neutral twist position to a first twisted position; and issue a third set of instructions to the pair of drive units when the joystick stalk is in the first non-neutral pivot position and the first twisted position, wherein each of the first set of instructions, the second set of instructions, and the third set of instructions cause a different direction of travel of the vehicle relative to each other.
2. The control system of claim 1, wherein the first direction is a clockwise direction with respect to a viewpoint of an operator of the vehicle, and the second direction is a counter-clockwise direction with regard to the viewpoint of the operator.
3. The control system of claim 2, wherein the second set of instructions are configured to cause:
- (i) a first zero turn operation of the vehicle in a clockwise vehicle direction when the joystick stalk is twisted in the clockwise direction about the stalk axis and
- (ii) a second zero turn operation of the vehicle in a counter-clockwise vehicle direction when the joystick stalk is twisted in the counter-clockwise direction about the stalk axis.
4. The control system of claim 2, wherein the third set of instructions are configured to cause a reduced speed of the left driven wheel relative to that of the right driven wheel when the joystick stalk is twisted in the counter-clockwise direction.
5. The control system of claim 2, wherein the third set of instructions are configured to cause a reduced speed of the right driven wheel relative to that of the left driven wheel when the joystick stalk is twisted in the clockwise direction.
6. The control system of claim 1, wherein the one or more controllers are further configured to issue a fourth set of instructions to the pair of drive units when the joystick stalk is in the neutral twist position and a second non-neutral pivot position.
7. The control system of claim 6, wherein the third set of instructions are equal to the fourth set of instructions to cause a same direction of travel of the vehicle relative to each other.
8. The control system of claim 1, wherein a degree of rotation of the first twisted position corresponds with a speed at which the second set of instructions is configured to cause the vehicle to turn.
9. A vehicle comprising:
- a left drive unit independently powering a left driven wheel, and a right drive unit independently powering a right driven wheel, wherein the vehicle is capable of moving in a plurality of forward directions, a plurality of reverse directions, a clockwise zero turn motion, and a counter-clockwise zero turn motion;
- a joystick configured to provide instructions for the left and right drive units, the joystick being pivotable about a pivot point from a neutral pivot position through a plurality of non-neutral pivot positions offset from the neutral pivot position, each non-neutral pivot position corresponding to a speed of the vehicle and a direction of the vehicle, the joystick further being twistable in a clockwise direction and a counter-clockwise direction about a joystick axis from a neutral twist position;
- at least one controller in electrical communication with the joystick, the left drive unit, and the right drive unit, wherein the at least one controller is configured to: send a first set of instructions to the left and right drive units when the joystick is in a first non-neutral pivot position and the neutral twist position; and send a second set of instructions to the left and right drive units when the joystick is in the first non-neutral pivot position and has been twisted from the neutral twist position to a first twisted position, wherein each of the first set of instructions and the second set of instructions cause a different direction of vehicle travel relative to each other.
10. The vehicle of claim 9, wherein the at least one controller is configured to include a plurality of driving modes, and each driving mode maps a different set of speeds of the vehicle and directions of the vehicle corresponding to the plurality of non-neutral pivot positions.
11. The vehicle of claim 10, wherein the at least one controller is configured to permit selection of one of the plurality of driving modes only when the speed of the vehicle is zero.
12. The vehicle of claim 9, wherein a maximum forward direction speed of the vehicle is greater than a maximum reverse direction speed of the vehicle.
13. The vehicle of claim 9, wherein the second set of instructions are configured to cause a reduced speed of the left driven wheel relative to that of the right driven wheel when the joystick is twisted in the counter-clockwise direction.
14. The vehicle of claim 9, wherein the second set of instructions are configured to cause a reduced speed of the right driven wheel relative to that of the left driven wheel when the joystick is twisted in the clockwise direction.
15. The vehicle of claim 9, wherein the at least one controller is further configured to send a third set of instructions to the left and right drive units when the joystick is in the neutral pivot position and has been twisted to the first twisted position.
16. The vehicle of claim 15, wherein a degree of rotation of the first twisted position corresponds with a speed at which the third set of instructions is configured to cause the vehicle to turn.
17. The vehicle of claim 15, wherein the at least one controller is further configured to send a fourth set of instructions to the left and right drive units when the joystick is in a second non-neutral pivot position and the neutral twist position.
18. The vehicle of claim 17, wherein the second set of instructions are equal to the fourth set of instructions to cause a same direction of travel of the vehicle relative to each other.
19. The vehicle of claim 15, wherein the third set of instructions provides for (i) zero turn operation of the vehicle in a clockwise vehicle direction when the joystick is twisted in the clockwise direction and (ii) zero turn operation of the vehicle in a counter-clockwise vehicle direction when the joystick is twisted in the counter-clockwise direction.
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Type: Grant
Filed: Jan 24, 2022
Date of Patent: Jan 30, 2024
Assignee: Hydro-Gear Limited Partnership (Sullivan, IL)
Inventors: Alyn Brown (Indianapolis, IN), Scott W. Keller (Charleston, IL)
Primary Examiner: Anshul Sood
Application Number: 17/582,598
International Classification: B62D 11/00 (20060101); B62D 11/04 (20060101);